POS1513 IDENTIFYING HIGH-RISK PROFILE IN PRIMARY ANTIPHOSPHOLIPID SYNDROME THROUGH CLUSTER ANALYSIS: FRENCH MULTICENTRIC COHORT STUDY
Authors: A. F. Guedon, L. Ricard, L. Charlotte, C. De Moreuil, G. Urbanski, S. Deriaz, G. Gerotziafas, I. Elalamy, A. Audemard, F. Chasset, S. Alamowitch, J. Sellam, J. J. Boffa, A. Cohen, C. Wahl, N. Abisror, F. Maillot, O. Fain, A. Mekinian
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombosis (arterial, venous or small vessel) or obstetrical events and persistent antiphospholipid antibodies (aPL), according to the Sydney classification criteria. Many studies have performed cluster analyses among patients with primary APS and associated autoimmune disease, but none has focused solely on primary APS. <h3>Objectives</h3> We aimed to perform a cluster analysis among patients with primary APS and asymptomatic aPL carriers without any autoimmune disease, to assess prognostic value. <h3>Methods</h3> In this multicenter French cohort study we included all patients with persistent APS antibodies (Sydney criteria) measured between January 2012 and January 2019. We excluded all patients with systemic lupus erythematosus or other systemic autoimmune diseases. We performed hierarchical cluster analysis on the factor analysis of mixed data coordinates results with baseline patient characteristics to generate clusters. <h3>Results</h3> We identified four clusters: cluster 1, comprising "asymptomatic aPL carriers", with low risk of events during follow-up; cluster 2, the "male thrombotic phenotype", with older patients and more venous thromboembolic events; cluster 3, the "female obstetrical phenotype", with obstetrical and thrombotic events; and cluster 4, "high-risk APS", which included younger patients with more frequent triple positivity, antinuclear antibodies, non-criteria manifestations, and arterial events. Regarding survival analyses, asymptomatic aPL carriers relapsed less frequently than the others, but no other differences in terms of relapse rates or deaths were found between clusters. <h3>Conclusion</h3> We identified four clusters among patients with primary APS, one of which was "high-risk APS". Clustering-based treatment strategies should be explored in future prospective studies. <h3>References</h3> [1] Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, Cervera R, Derksen RH, PG DEG, Koike T, Meroni PL, Reber G, Shoenfeld Y, Tincani A, Vlachoyiannopoulos PG, Krilis SA. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). <i>J Thromb Haemost</i>. 2006; <b>4</b>: 295-306. 10.1111/j.1538-7836.2006.01753.x. [2] Ogata Y, Fujieda Y, Sugawara M, Sato T, Ohnishi N, Kono M, Kato M, Oku K, Amengual O, Atsumi T. Morbidity and mortality in antiphospholipid syndrome based on cluster analysis: a 10-year longitudinal cohort study. <i>Rheumatology (Oxford</i>). 2021; <b>60</b>: 1331-7. 10.1093/rheumatology/keaa542. [3] Sciascia S, Radin M, Cecchi I, Bertolaccini ML, Bertero MT, Rubini E, Vaccarino A, Bazzan M, Giachino O, Baldovino S, Rossi D, Mengozzi G, Roccatello D. Identifying phenotypes of patients with antiphospholipid antibodies: results from a cluster analysis in a large cohort of patients. <i>Rheumatology (Oxford</i>). 2021; <b>60</b>: 1106-13. 10.1093/rheumatology/kez596. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.